[%c_effect e7;square;e7;type;GreatFind;persistent;true]
14. a2a4  14... g7g5 [%c_effect g5;square;g5;type;GreatFind;persistent;true] A typical Berlin move, gaining space on the kingside, which makes it difficult for White's pawns to advance. Furthermore, the knight cannot use the f4 square anymore. 15. c2c4 Reinforcing the knight's position and preventing any attempt by Black related to c5-c4. 15... d7e6  16. c1b2 